Background Antiphospholipid Syndrome (APS) is a known cause of thrombotic disorders, including Acute Myocardial Infarction (AMI). Although its incidence in AMI patients is not known, it may be an important factor in precipitating infarction, especially in younger adults.

Methods This is a case-control study consisting in 73 patients with Acute Myocardial Infarction, hospitalized at Cardiovascular Reanimation Clinic from 10 December 2015- 10 October 2019. All patients included in the study were from 23 to 50 years old. In the case-group were included 24 patients with Antiphospholipid Syndrome and Acute Myocardial Infarction, and 49 patients were included in the control group, which consisted only in patients with AMI, with no presence of APS. In every patient were gathered data such as complete blood count + ESR, Antinuclear Antibodies (ANA), Anti-cardiolipin antibodies (ACA), C3 and C4 complement fraction, Anti-ds-DNA, CRP and Ejection Fraction (EF) in echocardiography. Female patients were asked about their abortion history. As recommended in the guidelines, in positive results for APS, ACA levels were repeated after 12 weeks in order to establish the diagnosis. All data were gathered and statistically analyzed using Excel 2010 and IBM SPSS.

Results After comparing all gathered data, it was found that the patients with APS and AMI had a more significant tendency to have C3 hypocomplementemia (p=0.006), thrombocytopenia (p=0.002), a lower ejection fraction on transthoracic echocardiography (p=0.04) and a more elevated number of abortions before acute myocardial infarction (p=0.03) in comparison to the controls.

Conclusions From our study it was found that APS is not rare in young adults with AMI. It should be always suspected in young patients with no cardiovascular risk factors and there may be a characteristic clinical and laboratory picture in patients with AMI, which may suggest the APS diagnosis.

Acknowledgements The authors declare no conflict of interest.